Haematology - Haemophillia Flashcards
Definition
X-linked recessive inherited bleeding disorder. Genetic mutations in clotting factors of intrinsic pathway of coagulation:
- Haemophilia A = Factor VIII
- Haemophilia B = Factor IX
Haemophillia classification
Mild: 5-40% clotting factor level - severe bleeding with trauma and injury
Moderate: 1-5% clotting factor level - occasional spontaneous bleeding + severe bleeding with trauma and injury
Severe: <1% clotting factor level - frequent spontaneous bleeding + severe bleeding with trauma and injury
Aetiology
- Inherited = X-linked recessive
- Aquired = Px develops auto-antibodies against clotting factors
Epidemiology
FHx of haemophilia
Male
Acquired haemophilia risk factors
Age >60
Inflammatory bowel disease
Diabetes
Pregnancy
Postnatal
Malignancy
Pathophysiology
Delayed clot formation due to reduced thrombin generation , leading to excessive bleeding.
Signs
- Haemarthrosis: knees, elbows, ankles
- Prolonged bleeding following heel prick: common presentation in neonates
- Cutaneous purpura: often first presentation of acquired haemophillia
Symptoms
- Spontaneous bleeding: into muscles and joints
- Excessive bleeding: with limited trauma, post-dental surgery
- Easy bruising
- Fatigue
Diagnosis
FIRST LINE: Activated partial thromboplastin time (aPTT) prolonged
- Plasma factor VIII or IX levels decreased or absent
Mild to moderate haemophilia - no active bleeding treatment:
Education
Avoidance of high-risk activity
Joint strengthening exercises
Severe haemophilia - no active bleeding treatment
As above
Prophylactic clotting factors: IV replacement at least 45 weeks of the year
Haemophilia with recurrent bleeds into a single joint:
Radioactive synovectomy
Haemophilia with acute haemorrhage treatment
ABCDE assessment
Urgent haematology input
Urgent specialty input: e.g. surgeons for intra-abdominal bleeding, orthopaedics for intra-articular bleeding
Urgent clotting factor administration: aiming to maintain levels between 80-100%
Antifibrinolytic agents: tranexamic acid, aminocaproic acid
Desmopressin: benefit patients with haemophilia A
Haemophilia with acute haemorrhage and high levels of factor VIII or IX inhibitors treatment
Urgent haematology input
Bypassing agents: recombinant factor VIIa, factor VIII inhibitor bypassing fraction
Complications
Joint or muscular damage:
- contractures,
- synovitis,
- heterotopic ossification,
- arthropathy,
- muscle atrophy
Compartment syndrome
Life-threatening haemorrhage
Inhibitory antibodies to factor VIII or IX: more common in haemophilia A
Blood borne infections: from transfused blood products, less common now
